Alarm systems such as conventionally used for fire detection and capable of use for intrusion detection may have double detecting loops for greater immunity from failure. In the prior art such alarm systems were provided with means to shunt said loops should they break or short so that the alarm system could continue to function. In earlier devices the shunting was performed by manual switching by operators after an indication of a break or short. More complex circuity utilized a motor driven rotary switch to reset the system so that it might continue to function and to signal an alarm condition should one occur. Rotating the switch to reset for continued functioning involved a time delay of typically 15 seconds, and rotating the switch to signal an alarm took 45 more seconds, due to low gearing of the motor for the accuracy required. Such a lengthy time delay is too long for adequate fire protection and would permit intruders sufficient time to thwart the system.